The present invention relates to an oil separator that separates suspended-oil from a gaseous medium. More specifically, the invention relates to an oil separator having multiple angled inlets that facilitate the development of centrifugal force that achieves oil separation.
In compressors typically used in refrigeration and air conditioning systems, such as swashplate type compressors, a mist containing lubricating oil suspended in the gaseous refrigerant medium is often discharged from the compressor. That is, the high pressure refrigerant expelled by operation of the compressor frequently comprises a mist containing droplets of oil used to lubricate the moving parts of the compressor. Due to differences in various physical properties between the oil and the refrigerant, any oil that remains suspended in the refrigerant as it travels throughout the refrigeration circuit can reduce the performance of the compressor and refrigeration system. For example, by reducing oil available to the moving parts of the compressor, the compressor is susceptible to increased wear and seizure potential. Also, oil deposits on heat exchangers can reduce their efficiency.
To combat these problems, an oil separator can be added to the refrigeration circuit, and is typically positioned between the compressor outlet and condenser inlet. The oil separator functions to separate the suspended oil from the gaseous refrigerant. Several designs have been proposed for such oil separators. For example, commonly owned U.S. patent application Ser. No. 09/775,283, hereby incorporated by reference in its entirety, describes an oil separator that utilizes a lower portion having a decreasing diameter to increase centrifugal force exerted on a gas/lubricant mixture, and therefore facilitate oil separation. The oil separator of the previous application has a single tangential inlet for the gas/refrigerant mixture.
Considering the potential effects of oil being removed from the compressor due to its suspension in the refrigerant output, there is a need to improve the state of the oil separator art.
The present invention provides an oil separator that comprises a cylindrical portion, a plurality of inlets disposed on the upper wall and angled with respect to the lengthwise axis of the oil separator, a refrigerant outlet passage having inner and outer openings, a lower portion, and an oil outlet. The lower portion provides a cross-sectional diameter that decreases as the lower portion proceeds from top to bottom. Also, the present invention provides a swashplate type compressor and a refrigeration circuit that includes such an oil separator.